The above mentioned scientists propose to continue their existing program of research on arthropods of medical importance in Pakistan. With core support in Baltimore and Lahore (Pakistan Medical research Center) and in collaboration with Pakistani and third country scientists, eight interrelated projects are proposed: 1) Mosquito and disease ecology and genetic control. 2) Genetic studies to control Anopheles culicifacies. 3) Genetic control of Anopheles stephensi. 4) Genetic studies to control arbovirus vectors. 5) Epidemiology and ecology of human arbovirus diseases. 6) Studies on imported filariasis in Pakistan. 7) Clinical and epidemiologic studies on malaria and viral fevers. 8) Systematics, biology and vector potential of ticks. Particular emphasis is placed on developing new biological methods to control those arthropod species that transmit human pathogens. Genetic manipulation of vector mosquito species has been developed to the stage where field release trials of lab-reared populations, carrying deleterious genes, are currently in progress. Addtionally, field studies of mosquito predators and pathogens as control agents are continuing. A clinical component is being established that will relate these control projects directly to malarial and viral diseases. In a like manner a tick project is propsed, in order to define the role of ticks in the transmission of viral, rickettsial and protozoal agents.